Combination of e-boiler and gas boiler modernizes starch factory

The combination of an e-boiler and a high-efficiency gas boiler has modernized the energy supply for this starch factory. It boosts efficiency, responds to day-ahead energy prices, and helps stabilize grid imbalances. 

The outdated gas boilers were replaced by a smart duo: a 20 MW high-efficiency gas boiler and a 20 MW high-voltage electrode boiler. The gas boiler is designed for 8,000 operating hours per year, while the e-boiler runs about 2,000 hours annually thanks to its rapid response time. 

Which boiler is activated depends entirely on market prices. The choice is straightforward: 

• E-boiler when gas prices are high and twhen here is a surplus of electricity. 
• Gas boiler when electricity prices are high and when there is a power shortage 

As always we handled the complete balance of plant. The system is equipped with economizers, a feedwater tank, a deaerator, a blowdown tank, flash vessels, and superheaters. In short, everything needed for an optimal and efficient circuit. 

The control system was developed entirely in-house to guarantee flawless communication between the two boilers. The added requirement to react quickly to the aFFR market made the setup even more complex. 

 On top of that, any power taken from or delivered to the grid has to follow a stable curve within specific limits.

The steam circuit features several smart heat recovery techniques. The gas boiler, for example, is equipped with two economizers, and flash vessels are used to recover heat from low-pressure steam.